package com.hmdp.utils;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Component;

import javax.annotation.Resource;
import java.time.LocalDateTime;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;

@Component
@Slf4j
public class RedisIdWorker {
    @Autowired
    private StringRedisTemplate stringRedisTemplate;
    private static final long BEGIN_TIMESTAMP = 1640995200L;
    private static final int COUNT_BITS = 32;
    public long nextId(String keyPrefix){
        // 生成时间戳
        LocalDateTime now = LocalDateTime.now();
        long nowSecond = now.toEpochSecond(ZoneOffset.UTC);
        long timestamp = nowSecond - BEGIN_TIMESTAMP;

        // 生成序列号
        String date = now.format(DateTimeFormatter.ofPattern("yyyy:MM:dd"));
        long increment = stringRedisTemplate.opsForValue().increment("icr:" + keyPrefix + ":" + date);

        // 合并时间戳和序列号生成一个全局唯一id
        return timestamp << COUNT_BITS | increment;
    }
}
